CLyde Rear Shock

I am looking at building a bike from frame up I am starting with an Azonic Avenger frame and I am looking for a good 6" rear shock that can stand up to a 250lb beating. I dirt jump, trail ride, even hit up the street stuff everyone in a while so I need something that can take a beating. Your suggestions will be appreciated. Thanks guys!

I come in at about 225-230, and my XLT has been a new bike ever since I put the Manitou Metel R on it, bought at Chain Reaction Cycles. the 650 spring may be a bit bit stout, even for your slightly higher weight, so I suggest the 600. All told, when I get the 550 I'm looking at, I'll have less than $125 in the upgrade from the crap Swinger 3.

As a clyde there are a couple of things I look for in suspension:
1. Is it strong enough for my weight and aggressive riding style?
2. Is it tunable for my weight and the bike it is going onto?
3. If it breaks are parts readily available?

Out of the current shocks on the market I would probably lean towards a dhx5.0. It is a highly tunable shock via the external adjustments and if that isn't enough several companies can tune it specifically for you.